German Patent Application DE 198 06 576 A1 published Aug. 6, 1998 discloses a process wherein an oxygen-free pressurized nitrogen fraction is taken off from a pressure column. In order for the nitrogen to be also carbon-monoxide-free, the pressure column has at least 160 theoretical plates. However, the energy requirement for this, despite the 160 theoretical plates, is still very high. It is also a disadvantage that most of the ultrapure nitrogen is produced in the gaseous state.